长江口南汇嘴海域表层悬浮泥沙分布和运动遥感分析

利用Landsat-5/7卫星影像资料,建立了长江口南汇嘴水域表层悬沙遥感模式,结合实测含沙量资料对南汇嘴海区表层水体悬沙分布及泥沙运动情况进行了分析,结果表明南汇嘴附近海域总体上含沙量较高,在0.5～1.5kg/m3变化。高含沙量多出现在杭州湾口中部、南汇嘴浅滩,杭州北岸芦潮港附近含沙量为0.5kg/m3左右。悬沙的浓度及范围随大、小潮和洪、枯季的不同而不同。悬沙的浓度及范围随潮差和风速增大而增大,南汇嘴边滩含沙量一般洪季高于枯季,杭州湾水域水体含沙量一般是冬季高于夏季。长江口与杭州湾之间存在着泥沙交换,长江口水沙以直接和间接2种方式进入杭州湾,而南汇嘴近岸水域则是交换的主要通道。

Remote sensing analysis on distribution and movement of surface suspended sediment in the Nanhuizui tidal flat, Yangtze Estuary

According to the Landsat-5/7 remote sensing data and in-situ sediment concentration data acquired quasi-synchronously,the quantitative remote sensing model for suspended sediment in the Nanhuizui sea area of the Yangtze Estuary was set up.The results show that surface suspended sediment concentration is high with 0.5～1.5 kg/m3 in general.High suspended sediment concentration occurs in middle part sea area of the Hangzhou Bay and the Nanhui Shoal.Suspended sediment concentration is about 0.5 kg/m3 in the Luchaogang harbor sea area. Suspended sediment concentration is connected with the season and the tide.Current,wave,and coastwise flow control the distribution of suspended sediment.In the Nanhuizui tidal flat seasonal change of suspended sediment shows that summer concentration is higher than winter,but in the Hangzhou Bay seasonal change of suspended sediment shows that winter concentration is higher than summer.There exists sediment exchange between the Yangtze Estuary and the Hangzhou Bay with direct and indirect way.The Nanhuizui waters are the main channel of the exchange.